how to change labels on jpg image?

My idea was:

load('vel1.jpg')
pim=vel1.jpg
xlabel('distance(km)')
ylabel('depth(km)')
C = colorbar('location','EastOutside');

set(get(C,'XLabel'),'String','velocity(m/s)')

Does not work, so I want the same image just with new xlabel and ylabel.

Answer 1

[Image Analyst]

Same as what? What is the pim variable? How are you displaying the image(s), if at all?